1. Field of the Invention
The present invention relates to a one-way clutch and in particular, it relates to an improved positive axial clutch of the type which transmits torque in one direction and free-wheels in the opposite direction.
2. Description of the Related Art
One way clutches of various types are presently known. Of such clutches, possibly the type most known, is the sprag clutch which includes inner and outer races having a number of so called sprags held in position by a cage. The sprags are configured such that rotation of one race in a first direction causes camming engagement of the sprags with the respective surfaces, whereas rotation in the opposite direction causes free-wheeling of the clutch due to the fact that the sprags do not cam the surfaces in that direction.
U.S. Pat. No. 3,557,921 to Takada relates to a one-way clutch in which an inner and outer race has rollers interposed therebetween to effect one-way torque transmission while free-wheeling in the opposite direction. This clutch, however, presents a disadvantage in that the motion of the rollers is such as to cause their end portions to engage one of the clutch races when the clutch is placed in either the clutch engagement or free-wheeling mode thereby inhibiting the clutch motion and ultimately causing distortion of the race as well as the actual rollers. This distortion ultimately affects the clutch operation adversely in both directions. U.S. Pat. Nos. 1,670,157 and 1,834,843, both to Humphrey, disclose similar clutches which suffer from similar drawbacks.
U.S. Pat. No. 3,866,726 to Arenz relates to a releasable coupling which may be a clutch or a brake and which has a hollow member whose cavity is bound by an inner cylindrical wall. A stack of discs are inclined relative to the axis of the hub shell and the axis of rotation. Abutment means is provided for engaging the discs in an axial direction to provide movement of the discs toward and away from a locking engagement position with the inner wall of the hub steel. Other patents disclose related torque transmission devices which include U.S. Pat. No. 2,407,060 to Croft, U.S. Pat. No. 2,601,012 to Wolff, U.S. Pat. No. 2,401,864 to Gerst, U.S. Pat. No. 2,397,414 to Fast, U.S. Pat. No. 1,585,140 to Erban, U.S. Pat. No. 1,434,970 to Taylor, U.S. Pat. No. 575,988 to Rauhoff, U.S. Pat. No. 3,773 to Breslauer None of these patents disclose clutches wherein the inner and outer clutch races have hyperboloidal surfaces between which rollers are positioned to provide one-way clutch transmission, and opposite directional free-wheeling while supporting the rollers axially and permitting uninhibited rotational movement whenever required during clutch operation, particularly the free-wheeling mode. I have invented a clutch which avoids such disadvantages.